In the past, various and sundry apparatus and methods have been utilized for forming edgewise wound cores adapted for use in dynamoelectric machines. For instance, in some of the past apparatus and methods for forming edgewise wound cores, means, such as a punch press or multiple die or the like for instance, was intermittently operable to lance a continuous strip of generally thin ferromagnetic material into the desired configuration therefor, and such lanced continuous strip was intermittently fed from the lancing means to a means, such as a winding device or the like, which was also intermittently operable for deforming the lanced continuous strip generally edgewise thereof into a plurality of generally helical convolutions so as to effect the formation of an edgewise wound core. In at least some of the above discussed apparatus, the winding device was idle when the punch press was intermittently operable to lance the continuous strip, and alternatively, the punch press was idle when the winding device was intermittently operable to effect the generally edgewise deformation of the continuous strip fed thereto. While the above discussed past apparatus for forming edgewise wound cores undoubtedly exhibited many salient features, it is believed that at least one of the disadvantageous or undesirable features thereof was that the alternative operation or idleness of the punch press and winding device of such past apparatus resulted in an unnecessarily limited production capacity for such past apparatus.
Further, during the intermittent operation of some of the deforming devices utilized in the above discussed past apparatus, a pair of gripping elements of such past deforming devices gripped a pair of opposite faces of the lanced continuous strip between a pair opposite edges of such strip, and such gripping elements were thereafter conjointly oscillated through a preselected arc thereby to pull a section of the continuous strip through a cooperating deforming die or the like and effect the edgewise deformation of such strip section, i.e. deformation generally radially in the direction of the opposite edges thereof. Subsequent to each oscillation of the gripping elements through the preselected arc thereof, the gripping elements were operated to release the gripping engagement thereof with the opposite faces of the continuous strip, and thereafter the gripping elements are conjointly reversely oscillated through their preselected arc to their original positions where they were grippingly reengaged with the opposite faces of the continuous strip. Of course, the above discussed oscillations of the gripping elements through their preselected arc resulted in an intermittent pulling of sections of the continuous strip through the deforming die to effect the aforementioned deformed helical convolutions from which the edgewise wound cores were formed, and such oscillations of the gripping elements are believed to have occurred when the punch press was idle, as previously mentioned. While the above discussed past deforming device operable to intermittently pull the continous strip through a deforming die therefor undoubtedly disclosed many salient features, it is believe that at least one of the disadvantageous or undesirable features thereof was that the intermittent deformation of only sections of the continuous strip upon the oscillatory rotation of the gripping elements resulted in an unnecessarily limited production capacity for such past deforming device.
In other past apparatus, a plurality of pins in a rotary element were protractively movable therefrom into driving engagement between a plurality of teeth lanced into the continuous strip so as to drive or push the continuous strip through a deforming die to effect the aforementioned deformed helical convolutions from which the edgewise wound cores were formed. In this instance, the opposite edges of the strip were engaged between the deforming die and a part of the rotary element during the deformation of the continuous strip into the helical convolutions thereof. Of course, upon the deformation of the continuous strip into the helical convolutions thereof, the pins in the rotary element were retractively movable therein toward a position disengaged from the continuous strip. While this type of past apparatus utilizing the rotary element with reciprocally movable pins to engage and drive the strip through the deforming die undoubtedly had many salient features, it is believed that at least one of the disadvantageous or undesirable features thereof was that only one type of core could be manufactured thereon since it is believed that the reciprocating pins were not adjustable with respect to wear or to accommodate continuous strips having teeth lanced therein of different pitch or having different sized yoke sections. It is also believed that another disadvantageous feature or undesirable feature of such past apparatus utilizing reciprocally movable pins was that there was no adjustability therein to compensate for the various different amount of spring back encountered with respect to the use of different ferromagnetic material in the continuous strips being edgewise wound into cores.
In the formation of such past edgewise wound cores, the aforementioned lanced strip of generally thin ferromagnetic material was edgewise wound or deformed into a plurality of generally helical convolutions thereof, and such helical convolutions were accumulated into a generally annular stack thereof having a generally preselected stack height or length. Some of the aforementioned past lanced strips were laterally defined by a pair of generally parallel opposite edges, and a plurality of spaced apart teeth were formed on the strip generally lengthwise thereof with a tip of each tooth being defined by one of the opposite edges of the lanced strip, i.e., the tooth tip edge. The other of the opposite edges of the lanced strip defined a part of a yoke section which extended generally lengthwise thereof and from which the teeth extended generally laterally, and a plurality of winding receiving slots were provided in the strip between adjacent ones of the teeth and the yoke section, respectively. Each of the slots had a closed end at the yoke section extending generally parallel with the aforementioned other opposite edge or yoke section edge of the lanced strip and between adjacent ones of the teeth thereby to define a flat bottom slot, and an open end of each slot intersected the one opposite edge of the lanced strip between adjacent ones of the tooth tips.
When the aforementioned flat bottom slots were provided in the lanced strip, a plurality of segments were provided in the yoke section of the lanced strip extending generally between the one opposite edge thereof and the closed ends of the slots and such segments had a generally uniform cross-sectional area, respectively. The generally uniform cross-sectional areas of the segments in the yoke section of the lanced strip were, of course, effective to enhance the aformentioned edgewise and helical deformation of the lanced strip when it was edgewise and helically wound into the helical convolutions thereof during the formation of the edgewise wound cores since such edgewise winding required small unit deformations in the segments of the yoke section which was achieved by bending and stretching, i.e. stressing, the segments of the yoke section over the uniform cross-sectional areas thereof, respectively. When the helical convolutions of the edgewise wound lanced strip were accumulated into the generally axial stack thereof to define a respective one of the edgewise wound cores, as previously mentioned, the teeth on the lanced strip were arranged generally in axial row formation between a pair of opposite end faces of the core with the tips of the teeth defining in part a bore intersecting with the opposite end faces, and the flat bottom slots in the strip were also arranged generally in axial row formation so as to intersect with the opposite end faces of the core, respectively.
While the past edgewise wound cores having flat bottom slots therein, as discussed above, undoubtedly exhibited many salient features, at least one of the disadvantageous or undesirable features thereof is believed to be that it was difficult to position or place coils of windings into such flat bottom slots and achieve a desired slot fill of such coils. For instance, a pair of opposed corner sections were formed in the flat bottom slots generally at the juncture of adjacent pairs of the teeth with the closed ends of the flat bottom slots interposed therebetween. When the round insulated magnet wire of the winding coils was placed into the flat bottom slots, it is believed that such round wire of the winding coils had a tendency to move away from the corner sections of the flat bottom slots generally toward the center thereof. In other words, it is believed that the round wire of the winding coils would not fill the corner sections of the flat bottom slots thereby to establish voids therein which, of course, obviated achieving the desired or designed fill of the flat bottom slot with the winding coils. In order to achieve the desired or designed fill of the flat bottom slots with the round wire of the winding coils, it is believed that an additional manufacturing step was necessary, i.e., a winding press back operation, to move the round wire of the winding coils into the opposed corner sections of the flat bottom slots. Of course, this additional press back operation on the winding coils is also believed to be a disadvantageous or undesirable feature since it required additional expense for additional equipment and labor to effect such press back operation.
In other past lanced strips utilized in the formation of edgewise wound cores, one of the opposite edges of the lanced strip bounded the yoke section thereof, and the teeth on the lanced strip extended generally laterally from the yoke section thereof with the tips of the teeth terminating at the other of the opposite edgewise of the strip. The slots in the lanced strip between adjacent ones of the teeth thereof had an open end which intersected the other opposite edge of the strip between adjacent ones of the tooth tip, and a closed end of the slots provided at the yoke section between adjacent ones of the teeth had a generally arcuate or rounded configuration thereby to define a round bottom slot, respectively. When these round bottom slots were provided in the lanced strip, a plurality of segments were provided in the yoke section on the lanced strip generally between the one opposite edge or yoke section edge thereof and the closed ends of the round bottom slots and the cross-sectional areas of such segments were nonuniform. Therefore, when the lanced strip was edgewise deformed as it was edgewise wound into the helical convolutions thereof to form an edgewise wound core, as previously discussed, one of the disadvantageous or undesirable features is believed to be that greater forces were required to effect the edgewise deformation of the lanced strip due to the nonuniformity of the cross-sectional areas of the segments in the yoke section of the lanced strip. In other words, the unit deformations in the segments of the yoke section achieved by bending and stretching, i.e. stressing, such segments would be greater over the nonuniform cross-sectional areas thereof than would be if such cross-sectional areas were uniform. An analogous disadvantageous or undesirable feature is believed to be that greater stresses are imparted to the nonuniform cross-sectional areas of the segments in the yoke section of the lanced strip which are proportional to the aforementioned greater forces believed to be necessary to effect the deformation of the lanced strip having round bottom slots therein, as mentioned hereinabove. Thus, the more stress imparted to the lanced strip during the edgewise deformation thereof, the greater the spring-back of the lanced strip is believed to be subsequent to its edgewise deformation which is believed to result in less control over the tolerances or positions of the component parts of the strip with respect to each other when the accumulated helical convolutions of the lanced strip attain the preselected axial stack height thereof to form the edgewise wound core.